Battery and electronic equipment

Abstract

The utility model discloses a battery and electronic equipment, and the battery comprises a housing; the roll core is arranged in the shell; the buffer layer is arranged between the side surface of the shell and the side surface of the roll core; a pressure relief pipeline extending towards the end face of the shell is arranged in the buffer layer. Through the mode, the safety of the battery can be improved.

Description

Technical Field

[0001] The present application relates to the field of energy storage technology, and in particular to a battery and an electronic device. Background Art

[0002] Cylindrical batteries are becoming more and more popular in the new energy industry due to their good consistency, low cost, and ease of automation. Many new energy vehicles are gradually using cylindrical batteries to replace square batteries and soft-pack batteries. However, cylindrical batteries also have their own defects. For example, the cylindrical battery group margin (i.e., the ratio of the actual internal cross-sectional area to the maximum internal cross-sectional area) is close to 100%, resulting in a very large expansion force at the end of the battery cycle, which in turn makes the cycle life of cylindrical batteries lower than that of square batteries.

[0003] In particular, the safety of cylindrical batteries is relatively low. This is mainly because when a cylindrical battery experiences thermal runaway, the gas produced has a very scattered discharge path, which makes it possible for the entire cylindrical surface and both ends of the battery to rupture. The randomness is too great, which brings great difficulties to battery safety protection. Utility Model Content

[0004] To solve the above problems, the present application provides a battery and an electronic device, which can improve the safety of the battery.

[0005] A technical solution adopted in the present application is: to provide a battery, which includes: a shell; a winding core, which is arranged in the shell; a buffer layer, which is arranged between the side of the shell and the side of the winding core; wherein a pressure relief pipe extending toward the end face of the shell is arranged in the buffer layer.

[0006] In one embodiment, an air inlet connected to the pressure relief pipe is provided on one side of the buffer layer facing the winding core.

[0007] In one embodiment, a plurality of pressure relief pipes are disposed in the buffer layer, and the plurality of pressure relief pipes are distributed along the circumference of the winding core.

[0008] In one embodiment, one pressure relief pipe corresponds to a plurality of air inlets, and the plurality of air inlets are distributed along an extension direction of the corresponding one pressure relief pipe.

[0009] In one embodiment, a safety valve is further provided on the end surface of the shell, and the outlet of the pressure relief pipe faces the safety valve.

[0010] In one embodiment, the ratio of the diameter of the pressure relief pipe to the thickness of the buffer layer is less than or equal to 0.5.

[0011] In one embodiment, the thickness of the buffer layer is 0.5 mm-5 mm.

[0012] In one embodiment, the diameter of the pressure relief pipe is 0.1 mm-1 mm.

[0013] In one embodiment, the buffer layer wraps the core

[0014] In one embodiment, the battery also includes a current collector, the winding core includes an electrode sheet, the electrode sheet includes an electrode sheet body and a pole ear connected to each other, and the pole ear is connected to the current collector; wherein the pole ear includes at least one stretching portion, and the pole ear can be in at least a static state and a stretched state based on the external force applied to the stretching portion, and the length of the pole ear in the stretched state is greater than the length in the static state.

[0015] In one embodiment, the electrode tab includes a first connecting segment, a second connecting segment and a third connecting segment connected in sequence; wherein the first connecting segment connects the electrode body, the third connecting segment connects the current collector, and the second connecting segment includes at least one stretching portion.

[0016] In one embodiment, the stretching portion includes at least two sub-connecting portions, and the at least two sub-connecting portions are connected by a bending connection.

[0017] In one embodiment, the length of the tab in the stretched state is 1.2-1.5 times the length in the static state.

[0018] Another technical solution adopted by the present application is to provide an electronic device, which includes the battery as described above.

[0019] The battery provided by the present application includes: a shell; a winding core, which is arranged in the shell; a buffer layer, which is arranged between the side of the shell and the side of the winding core; wherein a pressure relief pipe extending toward the end face of the shell is arranged in the buffer layer. Through the above method, on the one hand, by adding the design of the buffer layer, the side wall of the shell can be protected when the winding core has thermal runaway, and the impact force on the shell can be reduced; on the other hand, by arranging a pressure relief pipe inside the buffer layer, the gas is directed to the two ends of the shell, and the impact force on the shell is further reduced, so that the winding core can spray the valve in a directional manner without exploding; therefore, the cycle performance and thermal safety of the battery are improved, thereby improving the safety of the battery.

[0020] In a further embodiment, by providing a stretching portion on the tab, the tab is prevented from being pulled during battery expansion, causing the pole piece to be subjected to external force, affecting the insertion or extraction of lithium ions, causing the battery to precipitate lithium, and causing cycle deterioration. At the same time, the tab is prevented from breaking under stress, leading to problems such as increased internal resistance. The tab designed in this scheme adopts a bending method to leave enough stretching space for the tab in the radial and axial directions. When the battery expands, the bent portion of the tab can be properly expanded to prevent the tab from being broken under stress or the pole piece from being subjected to pulling force. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 It is a structural schematic diagram of an embodiment of a battery provided by the present application;

[0023] Figure 2 is a schematic diagram of the structure of a pole piece and a pole ear in one embodiment;

[0024] Figure 3 yes Figure 2 A schematic structural diagram of an embodiment of the middle electrode tabs (positive electrode tab 41 and negative electrode tab 42);

[0025] Figure 4 is a schematic structural diagram of a buffer layer in one embodiment;

[0026] Figure 5 yes Figure 4 corresponding side cross-sectional view;

[0027] Figure 6 It is a structural schematic diagram of an embodiment of an electronic device provided by the present application.

[0028] Description of labels:

[0029] 100, battery;

[0030] 10, housing; 20, winding core; 21, positive electrode sheet; 22, isolation layer; 23, negative electrode sheet; 30, buffer layer; 41, positive electrode ear; 42, negative electrode ear; 51, positive current collector; 52, negative current collector;

[0031] 10a, safety valve; 21a, positive electrode sheet body; 23a, negative electrode sheet body; 31, pressure relief pipe;

[0032] A, first connecting section; B, second connecting section; C, third connecting section; S, sub-connecting part; 31a, air inlet;

[0033] Electronic equipment, 600. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0035] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0036] “A and / or B” includes the following three combinations: A only, B only, and a combination of A and B.

[0037] The use of "suitable for" or "configured to" in this application is meant to be open and inclusive language, which does not exclude devices that are suitable for or configured to perform additional tasks or steps. In addition, the use of "based on" is meant to be open and inclusive, because the process, step, calculation or other action "based on" one or more stated conditions or values ​​can be based on additional conditions or values ​​beyond the stated values ​​in practice.

[0038] In this application, the word "exemplary" is used to mean "used as an example, illustration, or description." Any embodiment described in this application as "exemplary" is not necessarily to be construed as being preferred or advantageous over other embodiments. The following description is given to enable any technician in the field to implement and use the present application. In the following description, details are listed for the purpose of explanation. It should be understood that a person of ordinary skill in the art can recognize that the present application can be implemented without using these specific details. In other instances, well-known structures and processes will not be elaborated in detail to avoid obscuring the description of the present application with unnecessary details. Therefore, the present application is not intended to be limited to the embodiments shown, but is consistent with the widest scope consistent with the principles and features disclosed in the present application.

[0039] See also Figure 1 , Figure 1 1 is a schematic structural diagram of an embodiment of a battery provided in the present application. The battery 100 includes a shell 10, a winding core 20 and a buffer layer 30.

[0040] The winding core 20 is disposed in the shell 10 ; the buffer layer 30 is disposed between the side surface of the shell 10 and the side surface of the winding core 20 , and optionally, the buffer layer 30 wraps the side surface of the winding core 20 .

[0041] Optionally, in one embodiment, the housing 10 is used to accommodate the entire internal structure, and the housing 10 is generally made of aluminum or steel.

[0042] Optionally, the winding core 20 includes a stacked positive electrode sheet 21, a separator 22, and a negative electrode sheet 23, and the positive electrode sheet 21, the separator 22, and the negative electrode sheet 23 are wound to form a winding structure. It can be understood that the winding structure (winding core) is a cylinder, the shell 10 is also a cylinder, and the buffer layer 30 is arranged between the inner side of the shell 10 and the outer side of the winding core 20, and wraps the winding core 20. It can be understood that the battery 100 in this embodiment is also called a cylindrical battery.

[0043] Optionally, in one embodiment, the positive electrode sheet 21 is mainly a positive electrode material (including LiFeO4, LiFexMnyO4, LiNixCoyMnzO2, conductive agent and binder, etc.) with a certain composition coated on aluminum foil, which mainly provides a Li (lithium) source. The negative electrode sheet 23 is mainly a negative electrode material (including graphite, conductive agent, binder, etc.) with a certain composition coated on copper foil. During the charging process, Li will be embedded in materials such as graphite, and the battery will expand.

[0044] Optionally, in one embodiment, the isolation layer 22 is a layer of material between the positive electrode sheet 21 and the negative electrode sheet 23, which has the function of isolating electrons and conducting ions, and is usually PP (polypropylene), PE (Polyethylene), or a composite material of PP and PE.

[0045] In a further embodiment, the battery 100 also includes a positive electrode ear 41, a negative electrode ear 42, a positive current collector 51 and a negative current collector 52. The positive current collector 51 and the negative current collector 52 are respectively arranged close to the two end surfaces of the shell 10. The positive electrode ear 41 connects the positive electrode sheet 21 and the positive current collector 51, and the negative electrode ear 42 connects the negative electrode sheet 23 and the negative current collector 52.

[0046] Optionally, in one embodiment, the positive electrode tab 41 is generally an aluminum foil, and the negative electrode tab 42 is generally a copper foil.

[0047] Optionally, in one embodiment, the positive current collector 51 is generally aluminum, and the negative current collector 52 is generally copper.

[0048] The positive electrode sheet 21 and the positive electrode tab 41 , and the negative electrode sheet 23 and the negative electrode tab 42 may be integrally formed, or may be connected by other fixing methods, such as welding.

[0049] It is understandable that during the cycle expansion process of the battery 100, as the pole pieces (positive pole piece 21 and negative pole piece 23) expand outward, the corresponding pole ears (positive pole ear 41 and negative pole ear 42) will be subjected to increasing pulling force, causing the pole pieces to deform or the pole ears to break, which will also have a serious impact on the cycle. Moreover, the force applied to the battery at the end is very large, which can easily cause the winding core 20 to deform or even break, explode, etc.

[0050] In one embodiment, in order to prevent the pole ear from being pulled during battery expansion, causing the pole piece to be subjected to external force, affecting the insertion or extraction of lithium ions, causing lithium deposition in the battery, and causing cycle deterioration, while avoiding the pole ear from breaking under stress, resulting in increased internal resistance and other problems, the pole ear of this embodiment includes at least one stretching portion, and the pole ear can be in at least a static state and a stretching state based on the external force applied to the stretching portion, and the length of the pole ear in the stretching state is greater than the length in the static state. In this way, sufficient stretching space is left for the pole ear in the radial and axial directions. When the battery expands, the stretching portion of the pole ear can be appropriately expanded. Avoid the pole ear from being broken by force, or the pole piece from being subjected to pulling force.

[0051] Optionally, the stretching portion may be a bending structure, a spring structure, etc.

[0052] like Figure 2 and Figure 3 As shown, Figure 2 is a schematic diagram of the structure of a pole piece and a pole ear in one embodiment, Figure 3 yes Figure 2 A schematic structural diagram of an embodiment of the middle electrode ears (positive electrode ears 41 and negative electrode ears 42), the electrode sheets include a positive electrode sheet 21 and a negative electrode sheet 23, the positive electrode sheet 21 includes a connected positive electrode sheet body 21a and a positive electrode ear 41, and the negative electrode sheet 23 includes a connected negative electrode sheet body 23a and a negative electrode ear 42.

[0053] Among them, the electrode ears (positive electrode ears 41 and negative electrode ears 42) include a first connecting section A, a second connecting section B and a third connecting section C which are connected in sequence; wherein the first connecting section A connects the electrode body (positive electrode body 21a or negative electrode body 23a), the third connecting section C connects the current collector (positive current collector 51 or negative current collector 52), and the second connecting section B includes at least one stretching portion.

[0054] Optionally, the stretching portion (second connecting section B) includes at least two sub-connecting portions S, and the at least two sub-connecting portions S are connected by a bend.

[0055] Specifically, it is assumed that the first connecting segment A and the third connecting segment C extend in the +Y direction. The first sub-connection portion S1 extends 45° toward +Y and deviates from the +X direction. It is assumed that the length extending in the +X direction is x0 and the length extending in the +Y direction is y0. Then, the second sub-connection segment S2 extends 45° toward +Y and deviates from the -X direction, and the length extending in the -X direction is x0 and the length extending in the +Y direction is y0, and so on. Figure 3 A total of 4 sub-connecting portions are shown in FIG. 1 , and therefore, the first connecting segment A and the third connecting segment C are aligned in the Y direction.

[0056] It is understandable that the more extensions there are, the better. The longer the extensions are, the more likely it is to affect installation and increase internal resistance. Generally, the length of the tabs (positive tab 41 and negative tab 42) in the stretched state is 1.2-1.5 times the length in the static state.

[0057] Further reading Figure 4 and Figure 5 , Figure 4 is a schematic structural diagram of a buffer layer in one embodiment, Figure 5 yes Figure 4 Corresponding to the side cross-sectional view, a pressure relief pipe 31 extending toward the end surface of the shell is provided in the buffer layer 30 so that when the gas pressure in the shell 10 increases, the gas is guided to the end surface of the shell 10 through the pressure relief pipe 31 .

[0058] Among them, the buffer layer 30 is generally made of PP, ABS (Acrylonitrile Butadiene Styrene plastic), PE or silicone. The thickness of the buffer layer 30 is generally 0.5 to 5 mm, which is selected according to the radius of the core 20 and the positive and negative electrode materials. For example, for the silicon-containing negative electrode, its expansion rate is very large, and a thicker buffer layer 30 is required to absorb its expansion pressure and thickness. When the core 20 expands, the buffer layer 30 provides buffering pressure so that the core 20 is not subjected to excessive force. At the same time, the group margin of the battery is appropriately reduced to increase the cycle life of the battery.

[0059] Optionally, the buffer layer 30 is provided with an air inlet 31a connected to the pressure relief pipe 31 on one side facing the winding core 20. It can be understood that the air inlet 31a faces the side of the winding core 20, and when the winding core 20 expands, the internal air pressure rises, and the gas enters the pressure relief pipe 31 from the air inlet 31a and is discharged from the two end surfaces of the shell 10 (up and down directions) in the extension direction of the pressure relief pipe 31.

[0060] Further recombining Figure 1In one embodiment, the end surface (top cover) of the housing 10 of the battery 100 is further provided with a safety valve 10a. The safety valve 10a is located on both sides of the top cover, and at least one outlet of the pressure relief pipe 31 faces the safety valve 10a. When the winding core 20 generates gas due to thermal runaway, the gas enters the pressure relief pipe 31 from the air inlet 31a and is released from the outlet of the pressure relief pipe 31 in the extension direction of the pressure relief pipe 31, thereby being ejected through the safety valves 10a on both sides, thereby preventing the battery 100 from exploding.

[0061] Optionally, in one embodiment, the buffer layer 30 is provided with a plurality of pressure relief pipes 31, which are distributed along the circumference of the winding core 20. One pressure relief pipe 31 corresponds to a plurality of air inlets 31a, which are distributed along the extension direction of the corresponding pressure relief pipe 31.

[0062] It can be understood that when gas is generated inside the core 20, the gas can be transmitted to the top cover through the pressure relief pipes 31 arranged around it, so that the core 20 can spray valves in a directional manner without "exploding". At the same time, the buffer layer 30 of this embodiment can also protect the side wall of the shell 10 and reduce the impact force when the core 20 has thermal runaway.

[0063] It can be understood that in one embodiment, the pressure relief pipe 31 can be formed by directly "hollowing out" the interior of the buffer layer 30, that is, the buffer layer 30 is equivalent to the pipe wall of the pressure relief pipe 31. In another embodiment, the interior of the buffer layer 30 can be "hollowed out" and then the pipe can be installed inside, that is, the pipe wall of the pressure relief pipe 31 is not the buffer layer 30. In this embodiment, the pressure relief pipe 31 can be made of hard materials such as ABS, PPS (Polyphenylene sulfide), and PDMS (polydimethylsiloxane).

[0064] Optionally, the thickness of the buffer layer 30 is 0.5 mm-5 mm, such as the thickness of the buffer layer is 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm or 5 mm.

[0065] Optionally, the diameter of the pressure relief pipe 31 is 0.1 mm-1 mm, generally not exceeding 1 / 2 of the thickness of the buffer layer 30. For example, the diameter of the pressure relief pipe 31 is 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm or 1 mm.

[0066] The effects of the above embodiment are described below through two sets of experimental data.

[0067] The first set of experiments tested the cycle performance of the battery, as shown in Table 1:

[0068]

[0069] As can be seen from Table 1 above, after 1500 cycles of charge and discharge of the battery at 25°C and 1C / 1C, the design of increasing the bending of the pole ear and the buffer layer is compared with the ordinary cylindrical battery (comparison of experimental group 2 / 3 / 4 / 5 and implementation group 1), the capacity retention rate is significantly improved and the internal resistance growth rate is significantly reduced. Therefore, increasing the bending of the pole ear and adding the buffer layer can significantly improve the cycle performance of the battery. Furthermore, in the design of increasing the bending of the pole ear and adding the buffer layer (comparison of experimental group 2 / 3 / 4 / 5), as the thickness of the buffer layer increases, the capacity retention first increases and then decreases, and the internal resistance growth rate first decreases and then increases. It can be seen that choosing the appropriate thickness of the buffer layer is particularly important for the cycle performance of the battery. For example, in the application scenarios of experimental group 2 / 3 / 4 / 5, a 1.0mm buffer layer can be selected.

[0070] The second group of experiments tested the thermal safety performance of the battery, as shown in Table 2:

[0071]

[0072] It can be seen from Table 2 above that with the addition of a buffer layer, the probability of explosion becomes lower and lower, and the thermal safety performance is significantly improved.

[0073] The battery provided in this embodiment includes: a shell 10; a core 20, which is arranged in the shell 10; a buffer layer 30, which is arranged between the side of the shell 10 and the side of the core 20; wherein, a pressure relief pipe 31 extending toward the end face of the shell 10 is arranged in the buffer layer 30, so that when the gas pressure in the shell 10 increases, the gas in the shell 10 is guided to the end face of the shell 10 through the pressure relief pipe 31. Through the above manner, on the one hand, by adding the design of the buffer layer 30, the side wall of the shell 10 can be protected when the core 20 has thermal runaway, and the impact force on the shell 10 can be reduced; on the other hand, by arranging the pressure relief pipe 31 inside the buffer layer 30, the gas is guided to the two ends of the shell 10, and the impact force on the shell 10 is further reduced, so that the core 20 can spray the valve in a directional manner without exploding; therefore, the cycle performance and thermal safety of the battery are improved, thereby improving the safety of the battery.

[0074] In a further embodiment, by providing a stretching portion on the tab, the tab is prevented from being pulled during battery expansion, causing the pole piece to be subjected to external force, affecting the insertion or extraction of lithium ions, causing the battery to precipitate lithium, and causing cycle deterioration. At the same time, the tab is prevented from breaking under stress, leading to problems such as increased internal resistance. The tab designed in this scheme adopts a bending method to leave enough stretching space for the tab in the radial and axial directions. When the battery expands, the bent portion of the tab can be properly expanded to prevent the tab from being broken under stress or the pole piece from being subjected to pulling force.

[0075] See also Figure 6 , Figure 6 1 is a schematic diagram of the structure of an electronic device according to an embodiment of the present application. The electronic device 600 includes the battery 100 as described in the above embodiment.

[0076] It is understandable that the electronic device 600 may be a new energy vehicle or a hybrid vehicle, or other electronic devices.

[0077] The display screen provided in the embodiment of the present application is introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A battery, characterized in that: The battery comprises: case; A winding core is disposed in the shell; A buffer layer is disposed between a side surface of the shell and a side surface of the winding core; Wherein, a pressure relief pipe extending toward the end surface of the shell is arranged in the buffer layer.

2. The battery according to claim 1, characterized in that An air inlet connected to the pressure relief pipe is arranged on one side of the buffer layer facing the winding core.

3. The battery according to claim 2, characterized in that A plurality of the pressure relief pipes are arranged in the buffer layer, and the plurality of the pressure relief pipes are distributed along the circumference of the winding core.

4. The battery according to claim 2, characterized in that One pressure relief pipe corresponds to a plurality of air inlets, and the plurality of air inlets are distributed along the extension direction of the corresponding pressure relief pipe.

5. The battery according to any one of claims 1 to 4, characterized in that: A safety valve is also provided on the end surface of the shell, and the outlet of the pressure relief pipe faces the safety valve.

6. The battery according to any one of claims 1 to 4, characterized in that: The ratio of the diameter of the pressure relief pipe to the thickness of the buffer layer is less than or equal to 0.

5.

7. The battery according to any one of claims 1 to 4, characterized in that: The thickness of the buffer layer is 0.5 mm-5 mm.

8. The battery according to any one of claims 1 to 4, characterized in that: The diameter of the pressure relief pipe is 0.1mm-1mm.

9. The battery according to any one of claims 1 to 4, characterized in that: The buffer layer wraps the winding core.

10. The battery according to claim 1, characterized in that The battery further comprises a current collector, the winding core comprises an electrode sheet, the electrode sheet comprises an electrode sheet body and an electrode tab connected to each other, and the electrode tab is connected to the current collector; The pole lug includes at least one stretching portion, and the pole lug can be in at least a static state and a stretching state based on the external force applied to the stretching portion, and the length of the pole lug in the stretching state is greater than the length in the static state.

11. The battery according to claim 10, characterized in that The pole lug comprises a first connecting section, a second connecting section and a third connecting section which are connected in sequence; Wherein, the first connecting section is connected to the pole piece body, the third connecting section is connected to the current collector, and the second connecting section includes at least one stretching portion.

12. The battery according to claim 10 or 11, characterized in that: The stretching portion includes at least two sub-connecting portions, and at least two of the sub-connecting portions are bent and connected to each other.

13. The battery according to claim 10 or 11, characterized in that: The length of the pole ear in the stretched state is 1.2-1.5 times the length in the static state.

14. An electronic device, characterized in that: The electronic device comprises the battery according to any one of claims 1-13.

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